题解 | 素数判断

#include<bits/stdc++.h>
using namespace std;
bool foo (int num){
    if (num <=1){
        return false;
    }
    if (num == 2){
        return true;
    }
    if (num%2==0){
        return false;
    }
    for (int i =3;i<sqrt(num);i +=2){
        if(num%i==0){
            return false;
        }
    }
    return true;
}
int main(){
    int T;
    cin >> T;
    int a[T];
    for(int i =0;i<T;i++){
        cin >>a[i];
        if(foo(a[i])){
            cout <<"Yes"<<endl;
        }
        else{
            cout <<"No"<<endl;
        }
    }
    return 0;
}
bool 函数用来筛选